Trending @Capgemini; Seeking Advice on Handling Irrelevant Task Assignments

I'm looking for some professional advice. Two months ago, my project ended, and since then, I’ve been on the bench. My manager has assigned me tasks that don't align with my skills and experience. I requested more suitable projects, but was told to mark these tasks as non-billable and continue with them.I communicated to my manager that these tasks don't match my skill set, and I was left undisturbed for a while. During this time, I took the initiative to learn new things and update my skills. However, my manager has started assigning me irrelevant tasks again.How should I address this situation professionally? Any suggestions or advice would be greatly appreciated.